Cargo ships



J. A. CLAY CARGO SHIPS Sept. l0, 1968 Filed July 6, 1967 INVENTOR A JOHN A. CLAY United States Patent O 3,400,681 CARGO SHIPS John Armstrong Clay, Bowdon, England, assignor to Turnbull Marine Design Company Limited Filed July 6, 1967, Ser. No. 651,461 Claims priority, application Great Britain, July 18, 1966,

2 Claims. (Cl. 114-435) ABSTRACT OF THE DISCLOSURE The invention provides a deep-sea cargo vessel having a dock compartment substantially midway along the length of the vessel with an opening through which barges or other vessels may be floated into and from the dock compartment, a lifting device, e.g., a gantry crane, for transferring the vessels between the dock compartment and storage compartments provided forward and aft of the dock compartment, and a watertight door for closing the access opening.

The present invention relates to deep-sea cargo ships.

A considerable factor in the economics of overseas trade are the periods of time during which ships are found in port for the purposes of off-loading cargo and taking on new cargo. One proposal which has been made with a View to overcoming this problem is that such ships carry barges loaded with goods to be imported, which barges can be off-loaded from a ship clear of a port, for example in a river estuary, and replaced by other loaded barges carrying goods to be exported.

While the tonnage of goods carried by cargo ships will manifestly be less where the hitherto-conventional practise is replaced by loaded barges, this disadvantage will be more than offset by the quick turn-around of the ships.

Cargo ships adapted to carry loaded barges must be equipped with a crane which can handle loads of the order of 250 to 300 tons, or thereabouts, and the loading and o-loading of such -barges creates another problem.

Proposals heretofore made have favoured loading and off-loading over or through the stern of the ship. One such proposal has been to lift or lower loaded barges over the stern of a ship but this presents considerable difculties in maintenance of the trim of the ship. Another such proposal has been to provide a well opening into the stern of the ship and into and from which loaded barges can be floated, the cranes then handling such barges from and to the well. This proposal mitigates the problem of maintenance of the trim of the ship during handling of the loaded barges but manifestly raises other problems in ship design and propulsion.

According to the present invention, a deep-sea cargo ship has substantially midway along the length of the ship a watertight dock compartment with an access opening through which barges or other vessels can be floated to and from the dock compartment and means for forming a watertight closure over the access opening. The dock compartment is ooded and the closure means opened when it is desired to oat one or more of the barges into or from the dock compartment, and the closure means are closed and the dock compartment is pumped out when the ship is prepared for a voyage. Lifting means are provided for transferring the barges between the dock compartment and storage compartments aft and forward of the dock compartment.

Further features of the invention will be evident from the following description, which is given by way of example, of the embodiment thereof illustrated in the accompanying drawings, wherein:

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FIGJ shows a side view in section of a deep-sea cargo ship according to the present invention;

FIG. 2 shows a plan view of the cargo ship of FIG. 1;

FIG. 3 shows a view taken in section along the line III-III of FIG. 2.

As shown in the drawings, a cargo ship indicated generally by reference numeral 10 is divided by watertight bulkheads 11 into a plurality of compartments including a dock compartment 12 extending transversely of -the ship 10 and disposed amidships, and three storage compartments acting as barge holds 14, of which two are provided forward of the dock compartment 12 and one is provided aft of the dock compartment 12.

At opposite ends of the dock compartment 12, doors 15 are provided for closing access openings 16, of which only one is shown (FIG. 3), in opposite sides of the hull of the ship 10.

Each door 15 is provided around its access opening 16 with a sealing device 18 comprising a hose which can be inflated, e.g. by air, water or oil, to form a watertight seal between the door 15 and the hull of the ship 10. Moreover, each door 15 is pivotal about a horizontal axis adjacent its upper edge by means of a hydraulic hinge 19 comprising a space into which oil can be pumped to act on a radial iin (not shown) to pivot a shaft (not shown) carrying the door 15 through 90. The two doors 15, their sealing devices 18 and their hydraulic hinges 19 are of known design and are therefore not described in detail in this specification.

A sluice valve arrangement 20 provided with a strainer 21 is disposed in the dock compartment 12 and communicates through the hull with the sea water so that by opening the sluice valve arrangement 20 the dock compartment 12 can be flooded. A pump 22 connected in a suction pipe 23 extending to the bottom of the dock compartment 12 is provided for pumping water from the dock compartment 12.

Two rails 24 extend longitudinally of the ship 10 on opposite sides of the dock compartment 12 Iand the barge holds 14 and a gantry crane 26 is mounted for movement along the rails 24 over the dock compartment 12 and the barge holds 14.

When the ship is to be loaded, the dock compartment 12 is flooded and at least one of the doors 15 is opened and retained in its open position by wire stays 27. Barges 29 carrying goods to be exported are then floated in succession into the dock compartment 12 through the open access opening. Usually, it is the door 15 on the leeward side of the ship 10 which is opened, although in calm weather both doors 15 may be opened.

The barges 29 are transferred from the dock compartment 12 to the barge holds 14 by the gantry crane 26, which lifts the barges 29 and stacks them in the barge holds 14 as shown in FIG. l. With both doors 15 in their closed positions and sealed to the hull of the ship by the sealing devices 18, the dock compartment 12 is pumped out and can be used as a hold. For unloading the barges 29, the dock compartment 12 is reooded, one or both ot the doors 15 is opened and the barges 29 are successively lowered into the dock compartment 12 by the gantry crane 26 and oated out of the ship to be towed by a tug.

Since the dock compartment 12 is located amidships, the trim of the ship 12 is not substantially upset during loading and unloading, and there is no interference with the layout of the engine room.

I claim:

1. A cargo ship having a watertight dock compartment extending transversely of said ship and disposed substantially midway along the length of the ship, means defining in at least one side of and substantially midway along the length of said ship an access opening for allowing cargo barges to be oated through said access opening into said dock compartment, means for forming a watertight closure over said access opening, means for flooding said dock compartment, means for pumping water from said dock compartment, a plurality of storage compartments for said cargo barges, said storage compartments being disposed forward and aft of said dockcompartment, and lifting means movable over said dock compartment and said storage compartments for transferring said cargo barges therebetween.

2. A cargo ship as set forth in claim 1, wherein said closure means comprise a door pivotable upwardly into an open position and downwardly into a closed position about an axis above said access opening, and sealing means 1,013,087 12/1911 Couvrette 114-435 2,319,855 5/1943 Forsberg 114-435 2,351,478 6/1944 Boyle 114-435 2,370,916 3/1945 Reedy 114-435 X 2,988,036 6/1961 Mooneyhan et al.

3,273,527 9/1966 Goldman 114-43.5

u MILTON BUCHLER, Primary Examiner. 0

T. MAJOR, Assistant Examiner. 

